1. Technical Field
The present invention relates generally to liquid dispensers and applicators of the type wherein a premeasured supply of liquid is disposed in an applicator handle and selectively dispensed through the applicator. The invention has particular applicability in the field of aseptic surgery preparation, as a pre-operative surgical scrub system for use in the operating room.
2. The Prior Art
As part of the preparation for many surgical procedures, for example, a surgical operation, it is required that the affected area of the patient be antiseptically cleansed. This requirement has existed for a very long time and the procedures used to meet this requirement have changed over the years. Originally, jars or cans of gauze, sponges or cotton balls were packed, sterilized and placed in operating rooms. These sponges and/or cotton balls are used for scrubbing procedures by holding them with sterile forceps and dipping them into a can containing a soap or antiseptic solution. After the cotton ball or sponge is saturated with solution, it is wiped onto the appropriate area. This procedure is inconvenient for a number of reasons. First, it tends to create a mess due to the open pan and the constant back and forth travel of the sponge or cotton ball between the pan and the patient. Further, the procedure takes an undesirably long time and results in an inordinate amount of liquid being lost due to splashing, scattering and waste. Moreover, this procedure tends to use more antiseptic solution than necessary because most medical personnel mistakenly believe that the antiseptic effect is more readily obtained if more solution is used. This is not true and, quite to the contrary, it has been noted that excess solution tends to form pools or puddles under the patient, resulting in iodine burns.
Apart from the disadvantage of the forceps and sponge or cotton ball procedures, the lack of standardization of techniques resulted in considerable confusion. Eventually, certain standards did develop. Specifically, the area of the incision on the patient's body must be cleansed thoroughly with a scrub or soap solution for a period of between 3-10 minutes. Most surgical operations, other than orthopedic surgery, require 3 minutes of scrubbing time; orthopedic surgery required 10 minutes of scrubbing time due to the increased risk of infection. After the scrubbing procedure, the area is dried with a sterile wipe and antiseptic solution is applied. For some procedures, other than orthopedic surgery, the scrub portion of the procedure is eliminated and only the antiseptic solution is applied. In either case, the standard procedure for applying either the scrub or antiseptic solution involves starting from the middle of the treated area and proceeding outward in circular or square motions, it being important never to return to a previously treated area with the same surface of the sponge. The sponge may be turned over and the same procedure started once again; that is, as long as a new sponge surface area is used, an already-prepared skin area may be re-contacted. However, one should never apply a used or contaminated sponge surface to a previously prepared skin area.
Attempts to overcome the drawbacks described above in relation to surgical swab and/or scrub apparatus and techniques involved the development of devices in which the liquid to be applied is contained within the device itself, generally in a hollow handle. Examples of such devices may be found in the following U.S. Pat. Nos. 1,221,227; 2,333,070; 3,324,855; 3,508,547; 3,614,245; 3,774,609; 3,847,151; 3,876,314; 3,891,331; 3,896,808; 3,958,571; 4,148,318; and 4,225,254. The devices disclosed in these patents present considerable improvements over the relatively primitive method of employing individual cotton balls or sponges with forceps and dipping these into the pan of solution as described above. However, many of the devices disclosed in the aforesaid patents are relatively complex to manufacture, thereby resulting in too high a cost for a device which is disposable after a single use. Moreover, many of the devices disclosed in these prior patents have only one available surface for the applicator sponge or swab. For example, the device disclosed in U.S. Pat. No. 4,225,254 provides a generally conical-shaped sponge, thereby making it difficult to assure that the same surface area of the sponge does not contact an already treated area of the patient' s skin. Moreover, the conical configuration minimizes the available surface area of the sponge. As noted above, available clean and unused surface area of the preparation sponge is one of the most important factors governing the pre-surgical preparation technique.
The device disclosed in U.S. Pat. No. 3,847,151 had considerable promise toward solving most of the problems referred to above. That patent discloses a surgical scrub device wherein a sponge applicator is mounted on a nozzle which extends from a hollow handle containing antiseptic solution. The nozzle includes a joint which can be selectively ruptured prior to use so as to permit the solution to flow from the nozzle into the sponge. In practice, however, this device proved to have functional problems. Mass production techniques being what they are, the stress break at the rupturable joint in the nozzle is not always complete and fluid is not always available. In addition, the rupture is not always properly completed by the user of the device, again resulting in a situation where fluid is not available for use. An additional problem with this device is that scrub solution (soap) tends to fill the sponge too slowly, whereas swab solution (antiseptic) tends to fill the sponge too quickly. In general, the product, although well conceived, has proven not to be reliable in use.
It has been suggested (see U.S. Pat. No. 3,481,676 to Schwartzman) that a liquid applicator may take the form of a cylindrical rupturable liquid-filled cartridge disposed in a tube-like handle having a sharp-edged flow passage disposed therein. The cartridge can be forced against the sharp edge to rupture the cartridge and extend the flow passage through the rupture. This permits liquid to flow from the cartridge, through the passage, to an applicator which surrounds the passage. The approach disclosed by Schwartman is valid for many applicators wherein a slow rate of fluid application can be tolerated. More particularly, in order for the liquid to be able to flow from the ruptured cartridge, there must be air admitted into the cartridge to replace the outflowing liquid. In the Schwartzman device, inflowing air and outflowing liquid must flow in opposite directions through the single sharp-edged flow passage. This severly limits the liquid outflow rate. For surgical scrub applications, it is important that the sponge or applicator be quickly saturated so that the liquid can be quickly applied to the pre-surgical incision site without delaying the surgical procedure. This problem could be remedied in the Schwartzman applicator by providing the cartridge with a valved or other permanent vent opening, much like is done with the cartridge-type fountain pens. However, such opening would not be a satisfactory solution for surgical scrub applications where the administered liquid must be maintained sterile in the cartridge.
In our aforesaid U.S. patent application Ser. No. 435,335, the subject matter of which is expressly incorporated herein by reference, we disclosed an improved surgical swab or scrub device wherein an elongated tubular handle has an applicator sponge permanently or removably secured to one end thereof and accepts the cylindrical cartridge of liquid at its other end. The sponge, which receives a flexible paddle-like member, has two opposite applicator sides. Two rigid hollow spikes are transversely spaced on opposite sides of the paddle-like member but inside the one handle end so as to point toward the other handle end. The spikes are in position to rupture a forward end of the cartridge when the cartridge is fully inserted into the handle, and to conduct liquid from the cartridge out to the sponge or applicator. The spikes are also positioned such that one or the other is always vertically higher than the other when the sponge is deployed for use with its applicator surfaces substantially horizontal. This difference in height reflects itself as a difference in liquid pressure at the punctures in the cartridge, whereby vent air can freely enter the cartridge through the lower pressurized upper puncture, thereby permitting liquid to freely egress through the lower puncture. The spikes are formed on respective diagonals which reside in respective bias planes which converge toward the said one end of the handle. This maximizes the spacing between two given puncture locations and thereby increases the liquid pressure difference at the puncture.
We have found that, for some liquids, even this increase pressure difference is not sufficient to satisfactorily distribute the liquid at a sufficient rate over a wide enough area of the applicator surfaces.